bisect ↔ to walk through Commit History via Binary Search to find good/bad Commits
git bisect start
to start bisect at last known working Commit
git bisect good
to mark Commit as good & continue bisect
git bisect bad
to mark Commit as bad & continue bisect
Whenever you bisect you are likely in damage control mode. It's easier said than done, but just don't commit bad code!
References
git bisect start↔ to startbisectat last known working Commitgit bisect good↔ to mark Commit as good & continuebisectgit bisect bad↔ to mark Commit as bad & continuebisect